Alcohol extraction
From Wiki Weed
Alcohol extraction — This method uses alcohol (preferably pure ethyl alcohol, but also isopropyl) as a solvent to strip cannabis of its trichomes and essential oils. After washing the plant material, the remaining alcohol is evaporated off, leaving behind a golden hash oil. Further processing via heat, agitation, or vacuum pressure will aid in removing any residual alcohol from the oil, which is essential prior to smoking, as well as result in different textures (shatter, budder, or oil).
